(aws-ecs): fromClusterAttributes requires VPC

I’m trying to fetch an ECS cluster based on its name, but security groups (mentioned here) and VPC (at least) are required.

Reproduction Steps

    Cluster.fromClusterAttributes(
        this, 
        "importedCluster",
        ClusterAttributes.builder()
            .clusterName(clusterName)
            .securityGroups(emptyList())
            .build()

What did you expect to happen?

I would expect fromClusterAttributes to have the same behaviour as aws ecs describe-clusters <clusterName>. The API clearly doesn’t require you to provide the VPC (or security groups), so why does this?

What actually happened?

Exception in thread "main" java.lang.NullPointerException: vpc is required

Environment

• CDK CLI Version: 1.78.0 (build 2c74f4c) and 1.83.0 (build 827c5f4)
• Node.js Version: v12.16.3
• OS: MacOS
• Language (Version): Kotlin (openjdk version “11.0.8”)

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This is 🐛 Bug Report

[mimozell]

I have a feeling they are making some really strange design decisions with cdk 😦 Not only do they go against expectations and logic (a unique ID should be enough to give you the object, such as the cluster), but also against what we are used to with the cli and sdk…

[tscully49]

We are having the same issue in a different context. In cloudformation, creating a fargate serivice only requires The short name or full Amazon Resource Name (ARN) of the cluster on which to run your service. If you do not specify a cluster, the default cluster is assumed. (from https://docs.aws.amazon.com/AWSCloudFormation/latest/UserGuide/aws-resource-ecs-service.html) and I would expect that to have similar behavior here. Instead, for CDK, to create a FargateService construct, I have to find the cluster with this function by passing both the securityGroups and VPC, when it seems a cluster name or ARN should be fine.